It is proposed to develop the chemical and analytical potential of mass spectrometry for applications to constituents of nucleic acids and their analogs. Techniques which will be studied and applied include gas chromatography-mass spectrometry and associated computer techniques, and field desorption mass spectrometry. High resolution mass spectrometry will be applied to structure determination of new nucleosides from transfer RNA, to fragmentation studies of nucleosides, bases and their deuterium labeled analogs, and to identification of metabolites from antitumor drugs.